Q3SqlPropertyMap Class Reference

Detailed Description

The Q3SqlPropertyMap class is used to map widgets to SQL fields.

The SQL module uses Qt object properties to insert and extract values from editor widgets.

This class is used to map editors to SQL fields. This works by associating SQL editor class names to the properties used to insert and extract values to/from the editor.

For example, a QLineEdit can be used to edit text strings and other data types in Q3DataTables or Q3SqlForms. Several properties are defined in QLineEdit, but only the text property is used to insert and extract text from a QLineEdit. Both Q3DataTable and Q3SqlForm use the global Q3SqlPropertyMap for inserting and extracting values to and from an editor widget. The global property map defines several common widgets and properties that are suitable for many applications. You can add and remove widget properties to suit your specific needs.

If you want to use custom editors with your Q3DataTable or Q3SqlForm, you must install your own Q3SqlPropertyMap for that table or form. Example:

 Q3SqlPropertyMap *myMap  = new Q3SqlPropertyMap();
 Q3SqlForm        *myForm = new Q3SqlForm(this);
 MyEditor myEditor(this);

 // Set the Q3SqlForm's record buffer to the update buffer of
 // a pre-existing Q3SqlCursor called 'cur'.
 myForm->setRecord(cur->primeUpdate());

 // Install the customized map
 myMap->insert("MyEditor", "content");
 myForm->installPropertyMap(myMap); // myForm now owns myMap
 ...
 // Insert a field into the form that uses a myEditor to edit the
 // field 'somefield'
 myForm->insert(&myEditor, "somefield");

 // Update myEditor with the value from the mapped database field
 myForm->readFields();
 ...
 // Let the user edit the form
 ...
 // Update the database fields with the values in the form
 myForm->writeFields();
 ...

You can also replace the global Q3SqlPropertyMap that is used by default. (Bear in mind that Q3SqlPropertyMap takes ownership of the new default map.)

 Q3SqlPropertyMap *myMap = new Q3SqlPropertyMap;

 myMap->insert("MyEditor", "content");
 Q3SqlPropertyMap::installDefaultMap(myMap);
 ...